JP3042759B2 - Manufacturing method of creeping discharge element for ozonizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a creeping discharge element for an ozonizer and a method of manufacturing the same. More specifically, a creeping discharge element equipped in an ozonizer for sterilizing, deodorizing, decoloring, etc., a gas, a liquid and a solid by ozone, and a creeping discharge element which is manufactured with high accuracy in terms of shape and dimensions, and a method of manufacturing the same About.

[0002]

2. Description of the Related Art Heretofore, a silent ozone generator using a glass discharge tube has been used as the ozonizer. However, since a silent ozone generator uses a glass discharge tube, the volume is originally large. Therefore, if the capacity is increased as the number of objects to be processed is increased, the aggregate of the glass discharge tubes becomes huge. In addition, cleaning or replacement is required for the glass discharge tube to become dirty or worn, and furthermore, the creeping discharge type ozonizer is gradually used because of low electric efficiency.

[0003] This creeping discharge method enables high-frequency discharge to increase the acceleration energy of electrons, thereby facilitating the ozonation reaction, and facilitating cooling of the discharge space because the discharge follows the surface. In addition, since the ceramic used for the dielectric layer is superior in mechanical strength and thermal shock characteristics as compared with the glass, it is possible to operate under low-temperature pressurization and achieve high efficiency. In addition, there is an advantage that the consumption of the discharge element is small.

However, as is known from the description of Japanese Patent Publication No. 22998/1990, a conventional surface discharge element simultaneously uses a corona discharge electrode and an induction electrode when firing fine ceramics to form a dielectric. It is manufactured by baking.

That is, as shown in FIG. 3, first, an alumina powder 51, a binder 52 and a dispersion medium 53 are mixed by a ball mill 54 or the like. Next, after the vacuum defoaming treatment V, an alumina green sheet 55 is formed by doctor blade molding or the like. Then, of the two alumina green sheets cut to a predetermined size,
A corona discharge electrode 56 is printed on the upper surface of 5a with a paste mixed with tungsten, and a protective film 57 is attached on the upper surface with a paste mixed with alumina powder. Further, the induction electrode 58 is printed on the upper surface of the other side 55b by the paste containing tungsten. Then, the other alumina green sheet 55b is connected to the induction electrode 58 by the one alumina green sheet 55b.
The surface 59a is bonded by a pressure press or the like so as to face the rear surface of the surface a, thereby forming a material 59 for the surface discharge element. This material 59
Is heated and fired in a non-oxidizing atmosphere of the firing furnace 60 because a metal electrode is printed.

[0006] The plate-like surface discharge element 61 is thus completed. Alumina green sheet is dielectric layer 6
It becomes 2.

The reason why tungsten is used as the electrode material is that it is selected especially because the shrinkage ratio during the firing is close to the shrinkage ratio of the alumina green sheets 55a and 55b as the material of the dielectric layer.

[0008]

However, the creeping discharge element 61 manufactured as described above has the electrodes 56 and 58.
Green sheets 55a, 5a, 5b,
Since 5b is integrally fired at a high temperature, it is difficult to adjust the distortion, and there is a limit in improving the dimensional accuracy.

As a result, for example, in the case of manufacturing a discharge unit having a laminated structure in which a plurality of steps of surface creeping discharge elements 61 are laminated, the joining method is limited and the good sealing property of the joint with the raw material gas introduction section and the like is obtained. Can not expect too. further,
When the size of the single surface discharge element 61 is increased, the dimensional accuracy may decrease in proportion.

For the above reasons, it becomes difficult to manufacture a high-precision and large-capacity ozonizer compactly.

The present invention has been made to solve such a problem, and since the dimensional accuracy can be improved, a creeping discharge element capable of maintaining high accuracy even in a large plate shape or a laminated structure can be maintained. And its manufacturing method.

[0012]

[0013]

[0014]

Means for Solving the Problems In manufacturing a surface discharge element for an ozonizer, a step of first firing a dielectric material made of fine ceramics in an air atmosphere to form a dielectric layer; A step of performing a quality check on the surface of the dielectric layer on one surface of the dielectric layer by a paste in which a powder of one of the metals described in the following (1) and (2) is dispersed. And printing a planar induction electrode on the other surface, and (1) an alloy mainly composed of molybdenum, (2) an alloy composed of silver and palladium, and leaving these electrodes as they are. A second firing step in a non-oxidizing atmosphere, wherein the quality check comprises:
Dimension inspections and repairs made based on the results of the dimensional inspections
It is characterized by a positive processing der Rukoto.

In the step of printing a corona discharge electrode and an induction electrode on the dielectric layer, a protective layer material made of fine ceramics or glass or a protective layer material made of resin is coated on the surface of the dielectric layer including each electrode after printing. It is preferable to add a coating step in the same manner as described above in that the electrode can be prevented from being worn due to electric discharge.

[0016]

According to the creeping discharge element manufacturing method of the present invention, the alumina green sheet before printing the electrodes is fired to form a dielectric layer. For example, after the firing, a dimensional inspection of the dielectric layer is performed. By performing grinding as needed, a dielectric layer with high dimensional accuracy can be formed. In the subsequent step of firing (printing) the printed electrode, only a small amount of heat is applied at a lower temperature than during firing of the alumina green sheet, so that there is no need to worry about distortion of the dielectric layer and skillfully. Since the selected electrode material does not inadvertently shrink due to baking, a sound electrode is formed. Thus, a high-precision creeping discharge element is manufactured.

Further, tolerance on product intermediate stage quality check <br/> line song Me manufacturing process, dimensional accuracy until after surface discharge element completed as conventional that after the dielectric layer formed as According to the process 30 in the present invention There is no such thing as being unclear. Moreover, since the firing of the alumina green sheet is usually performed continuously in a furnace in an air atmosphere, and the baking of the electrodes is performed in a batch in a furnace in a non-oxidizing atmosphere, the intermediate products are high before the batch processing. The product yield is good due to the finished dimensional accuracy. This has a remarkable advantage as compared with the conventional technique in which the dimensional accuracy is confirmed after the batch-type firing (after completion of the creeping discharge element).

Since the dimensional accuracy of the surface discharge element can be improved as described above, it is easy to increase the size. Furthermore, even when assembling such a creeping discharge element into a laminated structure, the joining method is not greatly limited, and the sealing property can be easily improved even at the joint with the raw material gas introduction portion, and the accuracy is improved. A good discharge unit can be manufactured.

[0019]

EXAMPLES Next, an embodiment of the process of creeping discharge element of the present invention with reference to the accompanying drawings.

FIG. 1A is a plan view showing an example of a creeping discharge element according to the manufacturing method of the present invention, and FIG.
FIG. 2A is a sectional view taken along line AA, and FIG. 2 is an explanatory view showing one embodiment of a method for manufacturing a surface discharge element of the present invention .

In FIG. 1, reference numeral 1 denotes a plate-shaped creeping discharge element. A linear corona discharge electrode 3 is formed on the upper surface of a dielectric layer 2 and a planar induction electrode 4 is formed on the lower surface. In this embodiment, the dielectric layer 2 is formed from alumina porcelain, and the electrodes 3 and 4 are formed from a molybdenum-containing metal. The reason why molybdenum was used as the electrode material was that the amount of heat applied during electrode baking was smaller than that during firing of the alumina green sheet, so that the particles shrank when the particles were sintered, corresponding to the dielectric layer 2 which hardly shrinks. This is because the metal needs to have a low rate. further,
Another purpose is to use a refractory metal as an electrode material in order to prevent damage to the electrode due to discharge when using the surface discharge element 1. With this in mind, other metals, such as niobium, tantalum or rhenium, can also be used as the counter electrode in the dielectric layer made of alumina porcelain.
Conversely, if the conventional tungsten electrode is to be baked, for example, on the fired dielectric layer of alumina porcelain, the electrode itself may be distorted or easily peeled off due to the difference in shrinkage.

On the other hand, the dielectric layer may be made of aluminum nitride or the like other than alumina porcelain.

In the figure, reference numeral 5 denotes a protective layer formed to prevent the electrodes from being worn by the discharge.

Further, metallized layers 6 and 7 are formed on the boundary surfaces between the electrodes 3 and 4 and the dielectric layer 2, respectively. The metallized layers 6 and 7 are composed of the dielectric layers 2 and 3 in which a slight component in the alloy containing molybdenum as a main component of the electrodes 3 and 4 is used.
Is a layer portion formed by diffusing and reacting in the alumina porcelain, and has an effect of firmly fixing the electrodes 3, 4 and the dielectric layer 2. Therefore, there is no possibility that the electrodes 3 and 4 are peeled off even during the use of the surface discharge element 1.

Next, a method for manufacturing the creeping discharge element 1 will be described with reference to FIG.

In FIG. 2, first, an alumina powder 11, a binder 12, and a dispersion medium 13 are mixed by a ball mill 14 or the like to form a viscous fluid slurry (FIG. 2).
(A)).

Next, after the vacuum defoaming treatment (FIG. 2B), an alumina green sheet 16 is formed by a doctor blade device 15 or the like (FIG. 2C).

Then, the alumina green sheet 16 cut to a predetermined size is heated and fired in an air atmosphere of a first firing furnace 17. The completed dielectric layer 2 is shown in FIG. 2 (d).

Although not shown, a dimensional inspection of the dielectric layer 2 is performed as necessary, and as a result of the dimensional inspection, the size and shape are adjusted as required by grinding or the like (distortion removal). .

Next, a linear corona discharge electrode 3 (see FIG. 1 (a)) is printed on the upper surface of the dielectric layer 2 with a paste mixed with an alloy powder containing molybdenum as a main component, and the lower surface thereof is also molybdenum. The induction electrode 4 is printed with a paste mixed with an alloy powder whose main component is (FIG. 2)
(E)).

Then, the protective film 5 is adhered to the upper surfaces of the electrodes 3 and 4 with a paste mixed with fine ceramic powder to form the material 18 for the surface discharge element. (FIG. 2 (f)).

Thereafter, the material 18 is transferred to the metal electrode 3,
4 is heated in a non-oxidizing atmosphere of the second firing furnace 19 (FIG. 2 (g)). By this heating, the protective layer 5 is formed, and the dielectric layer 2 and the electrodes 3, 4 are formed.
The metallized layers 6 and 7 (see FIG. 1B) are generated at the boundary surface between the layers. At the time of heating by the second firing furnace 19,
The amount of heat applied to the material 18 is much smaller than that in the first sintering furnace 17 in order to make the temperature lower by, for example, 50 to 100 ° C. as compared with the heating and sintering in the first sintering furnace 19. Therefore, there is no possibility that the dielectric layer 2 is distorted.

The plate-shaped creeping discharge element 1 thus completed (FIG. 2 (h)).

[0034]

According to the present invention, since the dielectric layer has a small distortion and a high dimensional accuracy, the surface discharge element can have a high accuracy even if it is formed in a large plate shape as well as a small one. Furthermore, even when assembling such a creeping discharge element into a laminated structure, the joining method is not greatly limited,
In addition, the sealing property can be easily improved even at the joint with the raw material gas introduction section, and a highly accurate discharge unit can be manufactured.

Further, in the method of the present invention, intends line quality checks in the middle stage of the product manufacturing process that after formation of the dielectric layer
Eyes, a good yield of the product.

[Brief description of the drawings]

FIG. 1A is a plan view showing an embodiment of a surface discharge element of the present invention, and FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A.

FIG. 2 is an explanatory view showing one embodiment of a method for manufacturing a surface discharge element of the present invention.

FIG. 3 is an explanatory view showing an example of a conventional method for manufacturing a surface discharge element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Surface discharge element 2 ... Dielectric layer 3 ... Corona discharge electrode 4 ... Induction electrode 5 ... Protective layer 6, 7 ... Metallized layer 11 ... Alumina powder 16 ...・ Alumina green sheet

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hyoe Ramino 1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries, Ltd. Inside the Akashi Plant (72) Inventor Shozo Okazaki 1-1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries, Ltd.

Claims (2)

(57) [Claims] 1. A step of forming a dielectric layer by first firing a dielectric material made of fine ceramics in an air atmosphere when manufacturing a creeping discharge element for an ozonizer, and checking a quality of the dielectric layer. And printing a linear corona discharge electrode on one surface of the dielectric layer with a paste in which a powder of one of the metals described in the following (1) and (2) is dispersed. Printing a planar induction electrode on the other surface; (1) an alloy containing molybdenum as a main component; (2) an alloy comprising silver and palladium; leaving these electrodes as they are in a non-oxidizing atmosphere. And the second baking step, wherein the quality check comprises a dimension inspection and a result of the dimension inspection.
Preparation of correction processing der Ru ozonizer for surface discharge element that is made based on. 2. The method according to claim 1, further comprising the step of :
In the process of printing the electrode, including each electrode after printing
Fine ceramic or glass on the dielectric layer surface
Protective layer material consisting of resin or resin
2. The ozonizer according to claim 1, further comprising an additional step of performing
Manufacturing method of creeping discharge element.